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Question About Capacitor Upgrade in Tube Amp

Hi,

I am preparing to do a coupling capacitor upgrade on a recently purchased tube integrated amp. The two 0.22uF on the preamp tubes are fairly straight forward. But I noticed another similar model 0.33uF cap on the large filter capacitor for the B+ supply that is installed across the hot lead to ground.

Does this cap on the B+ just block high frequency noise from the power supply or does it have any effect on the amp tone? Is there any reason to "upgrade" this cap?

I know it may be hard to tell exactly what is going on without a schematic.

Also any recommendations on a good cap to use in the upgrade of the coupling caps? I was looking at Mundorf SilverGoldOil for the quality at not too crazy a price. The amp already sounds good but lacks a little clarity that I think a coupling cap swap will help with. It is SET 300B amp.

Thank you!

 

calieng
calieng OP
203 posts
 

Thanks for the replies so far.

Did anyone know if the .33uF on the B+ filter cap is just for noise filtering on the power supply or does it have any effect on the amp sound? I probably will just leave that one alone unless someone one here has some advice for that one.

I will check out those other caps mentioned.

Thanks!

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noromance's avatar
noromance
10,491 posts
 

If you could fit one or more ClarityCap TC600 film caps in the power supply to replace the electrolytic, you’ll get a cleaner, blacker sound. They need 10 hours+ to break in from sounding plasticky. I've done this so I'm speaking from experience!

audioman58's avatar
audioman58
4,624 posts
 

It all depends on the room ,if space is not a issue buy far the best is the 

Duelund Tinned Copper foil paper oil caps ,

I have been modding for over 20 years and yes Humble homemade Hifi capacitor test is very informative , I-use Duelund in my Coupling caps in my Coda preamp section , they are Big  and take 4-500 hours to fully settle in , I tried vh audio Cutf, Odam , Millflex, JupiterCopper foil , Duelund is the Standard all others are judged by , Their silver foil has slightly better detail ,but I feel the Tinned copper foil oil 

fantastic banace and naturalness ,they are 2x+ bigger then most anything out there

thats the only draw back.

charles1dad's avatar
charles1dad
10,250 posts
 

Yes, much will depend on available interior space for capacitors and cost. If those are not limitations I’d choose Duelund for this project. Expensive but worth it based on my usage. How ever good this particular amplifier currently sounds, better quality coupling capacitors will take it further up the sound quality scale.

Charles

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